Description

Function to extract a sequence of default grapheme clusters from a text buffer, which must be encoded in UTF-8.

Parameters

haystack

String to search.

size

Maximum number items - based on the $extract_type - to return.

extract_type

Defines the type of units referred to by the $size parameter:

GRAPHEME_EXTR_COUNT (default) - $size is the number of default
grapheme clusters to extract.

GRAPHEME_EXTR_MAXBYTES - $size is the maximum number of bytes
returned.

GRAPHEME_EXTR_MAXCHARS - $size is the maximum number of UTF-8
characters returned.

start

Starting position in $haystack in bytes - if given, it must be zero or a
positive value that is less than or equal to the length of $haystack in
bytes, or a negative value that counts from the end of $haystack.
If $start does not point to the first byte of a UTF-8
character, the start position is moved to the next character boundary.

next

Reference to a value that will be set to the next starting position.
When the call returns, this may point to the first byte position past the end of the string.

Return Values

A string starting at offset $start and ending on a default grapheme cluster
boundary that conforms to the $size and $extract_type specified.